1. Field of the Invention
The present invention relates to a battery in which a cathode and an anode are oppositely arranged with an electrolyte layer in between.
2. Description of the Related Art
In recent years, many portable electronic devices such as a combination camera, a mobile phone, and a notebook personal computer have been introduced, and downsizing of such devices has been made. Therefore, research for improving the energy density of the secondary battery used as a power source for such electronic devices has been promoted. Specially, since a lithium ion secondary battery can provide a higher energy density compared to a traditional lead battery or a traditional nickel cadmium battery, the lithium ion secondary battery is widely used.
In the lithium ion secondary battery, as an anode material, carbon materials such as non-graphitizable carbon and graphite have been traditionally used. However, since the capacity of such carbon materials is already saturated, it is difficult to further obtain a higher capacity. Therefore, as an anode material, using silicon (Si) or tin (Sn) has been considered (for example, refer to U.S. Pat. No. 4,950,566).